The invention relates to an apparatus for extracting a blood component contained in a primary bag of a system of bags, as well as a method carried out using such an apparatus.
The invention applies to the field of blood transfusion, in particular in the treatment of blood, and notably the separation of blood components.
Whole blood is constituted of two types of components: blood cells comprising red blood cells, white blood cells and the platelets, and plasma wherein the blood cells are in suspension. Currently, only the blood components required for patients are transfused.
Today, in transfusion centers or hospitals, these various blood components are separated via centrifugation: the whole blood from a donor is collected in a bag referred to as the primary bag of a system of bags. Then, the system of bags is placed in a centrifuge in order to separate the various components. There are two types of centrifugation. The centrifugation referred to as gentle of the whole blood results in separating it into two layers: a lower layer rich in red blood cells called packed red blood cells (PRBC); and an upper layer containing plasma, platelets and white blood cells called platelet-rich plasma (PRP). Centrifugation referred to as hard results in a separation into three layers: a lower layer of PRBC; an upper layer of platelet-poor plasma (PPP); and an intermediate layer formed substantially of white blood cells and of platelets, referred to as the white blood cell-platelet layer or buffy coat.
The primary bag containing the components separated by centrifugation is then placed in an apparatus for separating components by compressing the primary bag, in such a way that, for example, the plasma is sent, via a tube, into a first satellite bag. An additive solution of the SAGM (saline—adenine—glucose—mannitol) type is moreover added to the extracted packed red blood cells in order to be able to store them up to 42 days.
An example of an apparatus for separating blood components is for example described in document EP 1 641 504. This separation apparatus is in particular provided with welding-clamps for quasi-automatic operation. However, with this type of apparatus, the operator must still manually break the circuit-openers of the system of bags. Furthermore, this apparatus does not make it possible to obtain a uniform mixture of the packed red blood cells and of additive solution.
However, it is also known that white blood cells have very substantial undesirable effects, which has led to seeking to eliminate them from blood components intended for transfusion. As such, the mixture of the packed red blood cells and of the additive solution is filtered through a white blood cell filter in order to eliminate the highest number of white blood cells as possible. But, if the mixture is not uniform, the filtration risks not being effective.
It is also known in documents DE 10 2007 002 291 and U.S. Pat. No. 5,836,934, apparatuses for separating and filtering blood components via compression. In these systems, the packed red blood cells and the additive solution are sent into a common tube, then the packed red blood cells to which an additive solution has been added is filtered and collected in a storage bag for red blood cells. These addition and mixing systems, although sufficient for carrying out filtration of the packed red blood cells in line under pressure, are not satisfactory in terms of mixing, when the packed red blood cells must be filtered via gravity.